A watchdog group on Thursday filed a legal request demanding William Schabas step down as the head of a United Nations-established fact-finding mission into Israel’s recent violent conflict with Gaza terrorists. It cited statements Schabas made that were critical of Israeli leaders and policies and supportive of Hamas, which the legal scholar two years ago termed a “a political party” representing the Palestinian people’s aspiration for statehood.

Schabas in 2012 expressed the wish to see Prime Minister Benjamin Netanyahu tried at the International Criminal Court, which clearly indicates that he is biased and thus unqualified to lead the investigation, UN Watch’s executive director Hillel Neuer said. “That statement alone is sufficient to disqualify Prof. Schabas on the question of whether he can impartially sit on this panel.”

Schabas voiced his opinions about Israeli policies vis-à-vis Gaza as recently as this summer, Neuer said. In one interview Schabas gave during the early days of Operation Protective Edge, he suggested Israel’s military response to fire emanating from Gaza was disproportionate and therefore could not be considered legitimate self-defense.

“We are filing the first formal legal request to Professor Schabas at the Human Rights Council, calling on him to recuse himself,” Neuer said at a press conference in Jerusalem. In any situation where a judge or the head of a fact-finding mission has been proven to be biased, or even if there is merely “the appearance of bias, the individual is obliged to step down,” he said.

Schabas remaining in place and leading the fact-finding mission “would have a potentially deleterious impact on the international rule of law,” Neuer writes in the request.

UN Watch’s legal request for Schabas to step down has been submitted as an official written statement to the upcoming session of the UN Human Rights Council and is set to be placed on its agenda for the September 22 debate on Israel. It will be distributed to the session’s delegates as an official document.

During the press conference, Neuer quoted several statements that Schabas, a Canadian international law professor, has made that appear to portray him as a fierce critic of Israel sympathetic to Hamas.

Some of Schabas’s comments about Israel and Israeli leaders have been reported widely in the Israeli and Jewish media — such as the desire to see Netanyahu indicted, or calling him “the single individual most likely to threaten the survival of Israel.” UN Watch’s 20-page text documents many other instances in which he either criticized Israel or called for Israeli leaders to be investigated for war crimes. In October 2012, for instance, he accused Jerusalem of “crimes against humanity, war crimes and the crime of aggression.”

Neuer cited an interview Schabas gave to the BBC on July 17, about a week after Israel launched Operation Protective Edge in response to incessant rocket fire from Gaza terrorist groups. Asked by the interviewer whether Israel’s actions could be seen as self-defense, given that Hamas rockets were fired at residential areas, Schabas replied that self-defense can only be used as a justification if it is “proportionate to the threat that’s being posed.” Since there are “huge numbers” of Palestinian civilian casualties but virtually none on the Israeli side, “prima facie, there is evidence of disproportionality in the response that Israel is undertaking in order to protect itself.”

With this interview, UN Watch argues in the legal brief, “Schabas effectively pronounced Israel presumptively guilty on the very question his commission in now called to investigate.”

During a legal symposium in 2012, the UN Watch document states, Schabas said Israel’s actions during the 2008-09 Operation Cast Lead were to be seen as “punitive actions” aimed at Gaza’s civilian population rather than self-defense. “If we look at the poor people of Gaza… all they want is a state — and they get punished for insisting upon this, and for supporting a political party in their own determination and their own assessment that seems to be representing that aspiration.”

In August, Schabas refused to say during an interview with Channel 2 whether he considers Hamas a terrorist organization, arguing that such an evaluation would prejudge the work of his fact-finding commission. But Schabas is no agnostic or neutral on the nature of Hamas, Neuer said. “Hamas, in Prof. Schabas’s view, very clearly is a legitimate political party that represents the aspirations of the Palestinian people for statehood. He does not talk about the war crimes committed by Hamas or the daily genocidal anti-Semitism.”